Refrigerating apparatus



y 3, 1956 R. w. DOEG 2,752,943

REFRIGERATING APPARATUS Filed Sept. 15, 1952 40 48 y- 25 f; 2 Z 62 M INVEN TOR.

RALPH k DOE'G BY W 21% l rran REFRIGERATING APPARATUS Ralph W. Doeg,Detroit, Mich., assignor to American Motors Corporation, a corporationof Maryland Application September 15, 1952, Serial No. 309,610

4 Claims. (Cl. 137-51215) This invention relates to refrigeratingapparatus and more particularly to refrigerant compressors and thedischarge valve mechanism therefor.

One of the objects of the invention is to provide an improved compressordischarge valve mechanism of a character to decrease valve operatingnoise and prolong usefulness of the valve.

Another object of the invention is to provide improved compressordischarge valve mechanism in which valve slap noise of a thin resilientpressure responsive reed valve or closure strip is substantiallyeliminated by convex stop surfaces and by restricting flexing of thevalve to portions thereof in the immediate vicinity of the dischargeports.

Another object of the invention is to provide, for controlling a pair ofdischarge or outlet ports, a single pressure responsive resilient reedvalve closure strip and associated mechanism arranged to dampen thenoise of the closure strip operation by confining flexing thereofnormally to areas of the strip directly over the ports, and in the eventof undue pressure on the strip, allow for full flexing action to avoidrupture or other damage to the closure strip.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings, wherein a preferred form of the present invention is clearlyshown.

In the drawings:

Fig. 1 is a fragmentary view in cross section of a re frigerantcompressor and discharge valve mechanism embodying features of myinvention;

Fig. 2 is a view similar to Fig. 1 showing certain parts of thecompressor and discharge valve mechanism in the positions they assume ondischarge operation; and

Fig. 3 is a detail sectional view of my discharge valve mechanism, takenalong line 3-3 of Fig. 1.

Referring to the drawings by characters of reference, there is shown acompressor cylinder block 20 having a bore 22 in which a piston 24 isadapted to reciprocate to compress gaseous refrigerant. A valve body orplate 26 covers the outer end of cylinder bore 22 to form a compressionchamber therewith, and mounted on said plate is a head 28. Screws (notshown) or other suitable securing means may be provided to hold theblock 2t), valve plate 26, and head 28 together, and to displacesuitable gaskets 34 to insure fluid tight joints between the parts.

In the valve plate 26 is an inlet port 36 and a pair of laterallypositioned outlet or discharge ports 38 that overlie the outer end ofthe cylinder for communication therewith. Within the cylinder head 28, apartition 40 separates inlet port 36 from outlet ports 38.

Held between gasket 34 and the under surface of valve plate 26 is a thinresilient reed suction valve or resilient plate 42 which closes inletport 36 on the compression stroke of the piston and opens the port onthe suction stroke of the piston. Any suitable type of suction valvenited States Patent ICC . may be used for controlling the inlet port,such for example as the valve shown in my Patent #2,372,938 issued April3, 1945.

Controlling the refrigerant discharge ports 38 is my improved valvemechanism which includes a resilient valve member or closure strip 44and a valve stop or backing plate 46. The resilient closure strip 44overlies both of the ports 38, and the backing plate is arranged tooverlie the closure strip 44 such that the closure strip is disposedbetween the opposed surfaces of the plates 26, 46. Backing plate 46 islocated by a pair of parallel pins 48 which have free fit with the plateto allow slight movement thereof toward and away from valve plate 46.The pair of pins 48 are respectively located outwardly of ports 38 andare fixed to valve plate 26. The pins 48 extend through the backingplate 46, and the outer ends of the pins support a stop member or rigidmetal strip 50 which holds a leaf spring 52 under tension againstbacking plate 46 for yieldingly urging the plate 46 against valve plate26.

Outer end portions of the resilient closure strip 44 are free to slideinwardly and outwardly to effect flexing, and in so doing aid indecreasing valve slap against the backing plate. The ends of the closurestrip 44 are preferably slotted, as at 54, to receive and to be guidedby the pins 48. Also the inner face of the backing plate 46 is recessedas at 56 for respectively receiving the end portions of the closurestrip, the recesses being sufliciently deep to allow free slidingmovement of the closure strip ends. Overlying respective end portions ofthe closure strip 44 are valve abutting stop surfaces 58 formed on theunderside of plate 46 to limit flexing action of the closure strip 44 insuch manner as to decrease appreciably so-called valve slap noiseoccasioned in the past by the flexible strip being slapped broadsideagainst a flat surfaced stop. To decrease such noise, I make the stopsurfaces 58 convex and arrange them to overlie respectively opposite endportions of closure strip 44, and to extend from said recesses 56inwardly and away from the closure strip to terminate at a central flatportion 62 of the backingplate 46. Thus, when closure strip 44 is flexedoutwardly as occurs on the compression stroke of piston 24, the oppositeends of the closure strip slide inwardly and at the same time roll onthe convex stop and in this way effect noise suppression.

In order to decrease further the operating noise of the closure strip44, I provide a coiled spring holding means 64 for holding the closurestrip 44 midway of its ends against flexing movement away from valveplate 26, thus restricting flexing action to end portions of the closurestrip or to portions in the immediate vicinity of and overlying ports38. From another aspect of the function of holding means 64 it may besaid that same allows only suflicient flexing to permit unrestrictedflow from ports 38 and prevents slapping and accompanying noise whichwould insue if the central portion of the closure member were allowed tocome up against the stop plate 46. For all normal operating pressures,the spring 64 will hold the central portion of closure strip 44 againstflexing. However, under certain abnormal conditions, the spring mayyield and allow full flexing of the reed valve to prevent rupturethereof. The holding spring 64 is held under compression between spring52 and the closure strip 44; the backing plate 46 being provided with aclearance hole 66 to receive the spring. Under other abnormal conditionsthe plate 46 may move away from valve plate 26 compressing spring 52 toallow free flow of fluid through ports 38 to prevent rupture of valve44. Thus in some instances springs 52 and 64 may both be compressed bymovement of valve 44 under abnormal conditions to permit the desiredflow from ports 38.

From the foregoing description it will now be understood that I haveprovided an improved discharge valve mechanism in which the valve orclosure strip operation noise is decreased materially by my provision ofconvex stop surfaces which restrict the thin resilient closure strip toa sliding rolling action to avoid valve slap and accompanying noise. Inaddition, I have provided in said mechanism, a yieldable holding meanswhich under normal operating conditions restricts flexing of the closurestrip to small areas thereof sufficient to allow free egress from theports controlled. in addition, the spring 64 will yield at abnormallyhigh pressures directed against the closure strip, thus to avoid anydanger of rupturing the strip or otherwise damaging the mechanism.

Although only a preferred form of the invention has been illustrated,and that form described in detail, it will be apparent to those skilledin the art that various modifications may be made therein withoutdeparting from the spirit of the invention or from the scope of theappended claims.

I claim:

1. In a compressor, a body having a pair of laterally positioned ports,a thin resilient closure strip overlying and controlling said ports andflexible away from said ports by pressure of fluid dischargingtherefrom, said closure strip having its opposite ends free to slide onsaid body to effect flexing of said resilient closure strip, meansguiding sliding movement of said closure strip, convex surface stopmeans for said closure strip overlying only outer end portions thereofand disposed on the other side of said resilient closure strip from saidbody, and spring means opposing movement of said resilient closure stripat a point intermediate said ports for all fiuid pressures below apredetermined pressure.

2. In a compressor, a valve body having a pair of laterally positionedports, a thin resilient closure strip overlying and controlling saidports and flexible away from said ports by a predetermined pressure offluid discharging therefrom, a backing plate overlying said closurestrip on the other side thereof from said body, said backing plate beingmovable away from said body in response to a predetermined pressurehigher than said first pressure acting against said closure strip, meanslimiting movement of said backing plate relative to said body, a leafspring interposed between said backing plate and said means, convex stopsurfaces on said backing plate facing said closure strip to limitflexing thereof, said convex surfaces curving inwardly from oppositeends of said closure strip and progressively away from said body, and acoil spring extending through said backing plate having its oppositeends respectively engaging said leaf spring and said closure strip andholding an intermediate portion of said closure strip to said bodyagainst flexing movement at pressures below said first predeterminedpressure.

3. In a compressor, a valve body having a pair of laterally positionedports, a thin resilient closure strip overlying and controlling saidports and flexible away from said ports by pressure of fluid dischargingtherefrom, said closure strip having its ends free to move inwardly, abacking plate overlying said closure strip on the other side thereoffrom said ports limiting flexing of said closure strip, pins extendingthrough said backing plate and retained by said body, slots in oppositeends of said closure strip receiving said pins and slidably guidedthereby during flexing of said closure strip, a rigid abutment memberextending between and supported by said pins on the other side of saidclosure strip from said body, a lead spring held under tension by andbetween said abutment member, and said backing plate urging the latteragainst said body, and a spring extending through said backing platehaving one end abutting said leaf spring and the other end abutting saidclosure strip at a point between said ports to hold a portion of saidclosure strip between said ports against movement during normal operating pressures.

4. In a compressor, a valve body having a pair of laterally positionedports, a thin resilient closure strip overlying and controlling saidports and flexible away from said ports by pressure of fluid dischargingtherefrom, said closure strip having its ends free to movelongitudinally with flexing action of the strip, a backing plateoverlying said closure strip, a pair of convex surface stops on saidbacking plate spaced apart and respectively overlying end portions ofsaid closure strip, said convex surfaces having curvatures extendingfrom adjacent the end portions of said closure strip inwardly and awayfrom the strip to present surfaces for the wrapping of the closure stripend portions thereon to decrease valve slap noise, and spring meansholding an intermediate portion of said closure strip between said portsagainst flexing under normal pressures.

References Cited in the file of this patent UNITED STATES PATENTS1,352,025 Prellwitz Sept. 7, 1920 1,390,941 Wainwright Sept. 13, 19211,568,195 Spreen Jan. 5, 1926 1,620,524 Luiz Mar. 8, 1927 1,629,495Frankenberg May 24, 1927 1,672,125 Heideman June 5, 1928 1,737,706Collins Dec. 3, 1929 1,915,694 Reindel June 27, 1933 1,949,710 DubrovinMar. 6, 1934 1,967,418 McPhail July 24, 1934 2,095,842 Steenstrup Oct.12, 1937 2,372,938 Doeg Apr. 3, 1945

